This miniseries was part of a trend in the 1990s where old anime was modernized for a new generation. However, unlike many other anime that were updated at the time, the creators decided to maintain a retro atmosphere with this one. The characters in it were designed in accordance with Mitsuteru Yokoyama's 1960s style, the vehicles in it were taken from the 20th century and reworked into a steam-punk story, and the mechanical designs in it combined high technology and old school engineering (exposed rivets and hidden weaponry). This set a trend for using the retro look in anime.
According to Yasuhiro Imagawa, the miniseries was influenced by Chinese wuxia tales (martial arts adventures with superhuman fighters), Chinese jiang hu tales (which feature clashes between clans and revolutionary plots) and the film El show de terror de Rocky (1975) (a world of incredible characters).
In this miniseries, Giant Robo's headdress bears a crest with a unicorn on it. In the original TV series El robot gigante (1967), Giant Robo (and its human controller, Daisaku Kusama) were members of a top secret peacekeeping organization known as Unicorn.
The character of Kenji Murasame had previously appeared in the original TV series El robot gigante (1967), but in that TV series he was just a normal police inspector, while in this miniseries he is an immortal superhuman.
The miniseries' director, Yasuhiro Imagawa, is a fan of early anime pioneer Mitsuteru Yokoyama, whose work was adapted for it.